航空发动机复杂曲面零件磨料水射流加工技术基础研究

Being geared to the urgent needs of national major projects and the development demand of Liaoning equipment manufacturing industry, and being aimed at the problems and challenges in machining high-performance parts with complex curved surface such as aero-engine blisks and impellers, fundamental research of abrasive waterjet (AWJ) processing technology is put forward. Lager machining allowance, strong geometric interference, poor processing performance, low efficiency, easy-deformation, serious tool wear, high cost and others are all difficult to be solved problems in existing aero-engine blisk processing methods which have severely impeded the development of domestic aviation industry. In this project proposal the mechanism of energy dissipation in AWJ will be first revealed. Then the material removal function based on the concavo-convex surface curvature variation and processing parameters will be established. Meanwhile, a strategy of real-time control for pressure and abrasive flow in AWJ processing is proposed. Furthermore, the processing path planning for complex curved surface in AWJ is created through multi-dimentional motion and physical parameters and the problems of accessibility for machining aero-engine blisk will be solved. The problems of “under processing” of concave surface and secondary damage of the warped surface in AWJ processing will be solved also. Based on the above research, typical blisk parts will be successfully machined by the AWJ process. That is, it is expectant to develop a new high efficient AWJ processing technology for aero-engine blisks and impellers with complex curved surface, which provides theoretical approaches and technical support for the improvement of key curved surface parts of national aviation major equipment and the technical progress of local equipment manufacturing enterprises.

面向国家重大工程应用和辽宁装备制造业发展迫切需求，针对航空发动机整体叶盘和叶轮为代表的高性能复杂曲面零件加工面临的去除余量大、强几何干涉、加工可达性差、效率低、易变形、刀具磨损严重、成本高昂等亟待解决的难题和挑战，开展复杂曲面零件磨料水射流加工技术基础研究，揭示磨料水射流喷射过程磨料能量耗散规律及凹凸曲面加工界面力学行为，建立虑及凹凸曲面的磨料水射流加工材料去除函数，发展磨料水射流加工过程磨料流量和水压实时精准调控技术，创立多维运动和多物理参量协调控制原理及数控加工曲面创成路径规划新方法，给出强几何约束条件下磨料水射流加工曲面可达性工艺策略，破解凹曲面“欠加工”和扭曲面二次损伤等难题，实现典型原理样件加工，形成航空发动机复杂曲面零件磨料水射流多维控形高效加工新技术，为显著提高航空复杂曲面零件加工效率，促进航空重大装备关键零件制造能力提升和地方装备制造企业技术进步，提供理论方法和技术支持。

针对航空发动机整体叶盘为代表的高性能复杂曲面零件面临的加工余量大、效率低、成本高等难题和挑战，充分考虑航空发动机整体叶盘零件强几何干涉、加工可达性差、材料难加工、低刚度结构、加工质量要求高等限制性因素，本项目开展了基于磨料水射流技术的复杂曲面零件多维控形高效加工技术研究，以服务国家重大工程应用迫切需求。.首先，研究了气体混入对高压水射能量损耗的影响，建立了气体混入对射流能量耗散影响以及气体混入对射流束发散程度影响的定量关系，并揭示了射流切面的气泡空化、溃灭导致的切割面形貌形成的机理。其次，在高压磨料水射流材料去除机理方面，揭示了磨料水射流冲蚀的材料去除机理，通过实验研究了磨料水射流加工的主要工艺参数对材料去除率的影响规律；通过量纲分析的方法，建立了磨料水射流加工的材料去除及切割深度预测模型。第三，建立了由零件三维模型反求零件水射流切割三维包络模型、射流喷嘴走刀路径生成方法，提出了虑及运动学约束的切割路径平滑遍历技术方案、解决了高曲率变化区域曲面切割优化问题，在切割过程引入了加工轨迹插补优化、切割头轴线方向矢量实施调整、冲蚀角补偿、磨料实时可控调节等调控方法，建立了运动量和物理参量协同调控的高压磨粒水射流复杂曲面加工技术及对应的高压水射流切割加工数控编程方法，解决了大厚度、难切割材料的三维复杂结构的型面可控切割问题。最后，构建了磨料定量供给、伺服电机控制切割水压的磨料水射流六轴数控切割实验平台，在该平台上采用40mm厚的TC4钛合金盘件，完成了整体叶盘样件的高压磨料水射高效切割加工实验，验证了本项目提出的航空发动机复杂曲面零件磨料水射流多维控形高效加工技术，为国家重大航空装备关键复杂曲面零件的制造和工业化批产能力提升提供理论方法和技术支撑。